Most of the models presented so far have followed one cohort in the first year under consideration, two in the second, three in the third, and so on. In addition, the models following ages 3 and up have relied on a preprocessing of the input data in order to ignore age groups zero through two. We now present a model which follows a fixed number of cohorts every year, without the need to preprocess the data.

NOTE that N is structured differently than for the models in the other sections. The same goes for catch and survey data in the input. Essentially, the diagonals of this N correspond to the N used in other models, and similarly for the catch matrix.